Scanning densitometer

Claim 2

A densitometer for measuring color characteristics of an object sample under test, comprising: an autonomously operating densitometer head comprising a scanner for generating electrical output signals representative of color characteristics of a scanned sample, a memory, a control unit for storing data representative of the electrical output signals in the memory, an optical coupler for transmitting and receiving optical signals, an electrical power source and circuitry connectable to an electrical connector for charging the power source; a densitometer support arrangement comprising a pair of essentially parallel transport bars for slidably supporting the densitometer head, a limit stop disposed along the transport bars, apparatus for raising and lowering the transport bars including a pair of rotatable shafts supporting the transport bars and a plurality of lever arms attached at each end of the shafts and a pair of links for interconnecting pairs of the lever arms at opposite ends of the shafts for concomitantly raising and lowering opposite ends of the support bars; a communication interface mounted in proximity of one end of the transport bars and comprising a connector for connection to a host computer and an interface optical coupler is responsive to electrical signals from the host computer to transmit optical signals and is responsive to received optical signals to transmit electrical signals to the host computer; the densitometer head further comprising drive apparatus engaging at least one of the transport bars, the control unit is responsive to an optical signal received via the optical coupler in the head to control the drive apparatus to move the densitometer head along the transport bars in the direction of the limit stop, the control unit is further responsive to electrical output signals from the scanner for storing data representative of electrical signals representing color density readings obtained from the scanner while the densitometer head is moved along the transport bars, control circuitry is responsive to detection of proximity of the limit stop to control the drive apparatus to move the densitometer head toward the one end of the transport bars and is responsive to detection of the one end of the transport bars for transmitting an optical signal to the interface optical coupler and is further responsive to an optical signal from the interface optical coupler to transmit optical signals representative of the stored data.

Claim 3

A densitometer for measuring color characteristics of an object sample under test, comprising: an autonomously operating densitometer head comprising an optical scanner for generating output data representative of color characteristics of an object sample exposed to the scanner and a memory for storing the output data; a longitudinally extending transport assembly for movably supporting the densitometer head adjacent an object sample; an interface unit disposed adjacent the assembly for connection to a host computer and comprising circuitry for transmitting and receiving signals; a connector device for providing a signal transmission connection between the head and the interface unit when the head is disposed within a predetermined distance of the interface unit; the densitometer head further comprising an electric motor for propelling the head along the transport assembly for exposing the object sample to the optical scanner, control circuitry responsive to a start signal received via the connector device for activating the motor and circuitry responsive to an input signal received via the connector device to transmit data stored in the memory to the interface unit via the connector device.

Claim 4

The densitometer in accordance with claim 2 wherein the connector device comprises an optical coupler on the interface unit and an optical coupler on the head, each for optically transmitting and receiving signals only when the head is within the predetermined distance of the interface circuit.

Claim 5

The densitometer head in accordance with claim 1 or 2 wherein the head further comprises a battery for providing electrical power for the head when the head is removed from the interface circuit by a distance greater than the predetermined distance.

Claim 6

The densitometer in accordance with claim 4 wherein the head further comprises a charging circuit connected to the electrical connector terminal on the head for charging the battery when the head is within the predetermined distance of the interface unit.

Claim 7

The densitometer in accordance with anyone of claims 2 to 5 wherein the transport assembly comprises a pair of spaced-apart, substantially parallel transport bars for slidably engaging the densitometer head.

Claim 8

The densitometer in accordance with claim 6 wherein the transport assembly comprises a pair of rotatable shafts, each supporting one of the transport bars, a plurality of lever arms, one attached at each end of each of the shafts and each having a support end for slidably engaging a support surface, and a pair of links interconnecting pairs of the lever arms at opposite ends of the shafts, whereby opposite ends of the support bars are concomitantly raised and lowered relative to the support surface when one of the shafts is rotated.

Claim 9

The densitometer in accordance with anyone of claims 2 to 7 and further comprising a limit stop disposed along the transport assembly, wherein the interface unit is disposed at one end of the transport assembly and wherein the head comprises a limit switch operated by engagement with the limit stop and the control circuitry is responsive to the start signal for activating the motor to propel the head in a direction away from the interface unit and responsive to operation of the limit switch to reverse direction of the motor.

Claim 10

The densitometer in accordance with anyone of claims 2 to 8 wherein the densitometer head comprises two data memories and is responsive to the receipt of parameter data from the interface unit for storing the parameter data in a first of the memories and is responsive to receipt of the optical scanner output data for storing the optical scanner output data in a second of the memories.

Claim 11

The densitometer in accordance with claim 9 wherein the densitometer head comprises circuitry for reading the parameter data and for performing data processing operations on the optical scanner output data in accordance with the parameter data prior to storing the output data in the second memory.

Claim 13

The method of claim 11 and further comprising the steps of detecting a distant end limit prior to the step of detecting and storing information.

Claim 14

The method of claim 11 or 12 after detecting an end-of-run condition and further comprising the steps of transmitting an end-of-run message to the host processor and waiting for a data request prior to the step of transmitting the stored data to the host processor.